fix(db): add missing apiKeys columns + restore ApiExplorerModal export

- schema.js: add createdAt/allowedModels to apiKeys, bump SCHEMA_VERSION 3->4
- shared/components/index.js: restore ApiExplorerModal barrel export (was replaced by TagInput)
- combos: tag support, repo + api + page updates

tmp/9r-smoke-dist/dev/cache/.rscinfo

@@ -0,0 +1 @@
+{"encryption.key":"+PzC19pP70GybS3k4K8t6RsdWKuh0Yqhwm2/p8Gxynw=","encryption.expire_at":1788861894573}

tmp/9r-smoke-dist/dev/cache/config.json

@@ -0,0 +1,7 @@
+{
+	"telemetry": {
+		"notifiedAt": "1787652294386",
+		"anonymousId": "603e54ced475f5c44789656952c172a5cb54960610abe0044c7cf55588e68b9b",
+		"salt": "2780e49a8a0d18bcf1e75adcca6c2702"
+	}
+}

tmp/9r-smoke-dist/dev/cache/turbopack/v16.3.1-3d32eb87/CURRENT

@@ -0,0 +1 @@
+{"max_sequence_number":0,"commit_time":"2026-08-25T10:04:54.578821Z"}